A pulmonary agent, or choking agent, is a

chemical weapon agent A chemical weapon (CW) is a specialized munition that uses chemicals formulated to inflict death or harm on humans. According to the Organisation for the Prohibition of Chemical Weapons (OPCW), this can be any chemical compound intended as ...

designed to impede a victim's ability to breathe. They operate by causing a build-up of fluids in the lungs, which then leads to

suffocation Asphyxia or asphyxiation is a condition of deficient supply of oxygen to the body which arises from abnormal breathing. Asphyxia causes generalized hypoxia, which affects primarily the tissues and organs. There are many circumstances that can ...

. Exposure to the eyes and skin tends to be corrosive, causing blurred vision and severe deep burns. Inhalation of these agents cause burning of the throat, coughing, vomiting, headache, pain in chest, tightness in chest, and respiratory and circulatory failure. Examples of pulmonary agents include: *

Chlorine gas Chlorine is a chemical element with the Symbol (chemistry), symbol Cl and atomic number 17. The second-lightest of the halogens, it appears between fluorine and bromine in the periodic table and its properties are mostly intermediate betwee ...

Chloropicrin Chloropicrin, also known as PS and nitrochloroform, is a chemical compound currently used as a broad-spectrum antimicrobial, fungicide, herbicide, insecticide, and nematicide. It was used as a poison gas in World War I. Its chemical structural f ...

(PS) * Diphosgene (DP) *

Phosgene Phosgene is the organic chemical compound with the formula COCl2. It is a toxic, colorless gas; in low concentrations, its musty odor resembles that of freshly cut hay or grass. Phosgene is a valued and important industrial building block, esp ...

(CG) *

Disulfur decafluoride Disulfur decafluoride is a chemical compound with the formula . It was discovered in 1934 by Denbigh and Whytlaw-Gray. Each sulfur atom of the molecule is octahedral, and surrounded by five fluorine atoms and one sulfur atom. The two sulfur atoms ...

Perfluoroisobutene Perfluoroisobutene (PFIB) is the perfluorocarbon counterpart of the hydrocarbon isobutene and has the formula (CF3)2C=CF2. An alkene, it is a colorless gas that is notable as a highly toxic perfluoroalkene. Few simple alkenes are as toxic. Saf ...

Acrolein Acrolein (systematic name: propenal) is the simplest unsaturated aldehyde. It is a colorless liquid with a piercing, acrid smell. The smell of burnt fat (as when cooking oil is heated to its smoke point) is caused by glycerol in the burning fat ...

Diphenylcyanoarsine Diphenylcyanoarsine, also called Clark 2 (Chlor-Arsen-Kampfstoff 2, being the successor of Clark 1) by the Germans, was discovered in 1918 by Sturniolo and BellinzoniSturniolo, G. und Bellinzoni, G. (1919); ''Boll. chim. pharm.'', 58, 409–410 an ...

is the most dangerous commonly used pulmonary agent (although disulfur decafluoride and perfluoroisobutene are both even more dangerous, with respectively 4 and 10 times the lethality of phosgene, neither is widely used). It is a colorless gas under ordinary conditions. It has a vapor density 3.4 times greater than that of air, allowing it to remain low in the air for long periods of times. Phosgene leads to massive pulmonary edema, which reaches maximum symptoms in 12 hours after exposure, followed by death within 24 to 48 hours.

Chlorine Chlorine is a chemical element with the symbol Cl and atomic number 17. The second-lightest of the halogens, it appears between fluorine and bromine in the periodic table and its properties are mostly intermediate between them. Chlorine i ...

is an element used in industry. It is one of the most commonly manufactured chemicals in the United States. It is used to make pesticides, rubber, and solvents. It is also used in drinking water and swimming pools to kill bacteria. The extent of poisoning chlorine causes depends on the amount of chlorine to which a person is exposed.

History

The first major use of these agents came on April 22, 1915, at the

Second Battle of Ypres During the First World War, the Second Battle of Ypres was fought from for control of the tactically important high ground to the east and south of the Flemish town of Ypres in western Belgium. The First Battle of Ypres had been fought the pr ...

in Belgium. The Germans opened up 168 tons of chlorine gas on the French, Canadian and British troops which created a wind-borne cloud of chemical gas that opened up a breach in the lines. However, the Germans were not prepared to exploit the opening. In 1917 the Germans also introduced the agent phosgene. By then both sides had mastered the techniques of new choking agents such as diphosgene, chloropicrin, and perfluoroisobutene which allowed numerous attacks to be made. By the end of World War I, phosgene was responsible for roughly 80% of all deaths related to chemical attacks.

References

* U.S. Army Medical Research Institute of Chemical Defense. (Sep. 1995)
Medical Management of Chemical Casualties Handbook: Pulmonary Agents
Retrieved Nov. 7, 2004. *Roland E. Langford, ''Introduction to weapons of mass destruction : radiological, chemical, and biological''. (Hoboken, New Jersey: Wiley-Interscience, 2004) *Reaching Critical Will.org

(11 May 2008). 6*RJ Smith.com
Chemical Agents
(11 May 2008). *Eric A. Croddy and James J. Wirtz, ''Weapons of Mass Destruction: An Encyclopedia of Worldwide Policy, Technology, and History''. (Santa Barbara, California: ABC-CLIO, 2005). {{Chemical agents